This invention relates to an apparatus for cleaning and opening fiber tufts, particularly cotton and synthetic fiber tufts wherein the fiber tufts, forming a fiber mass, pass through a feeding device such as a feed roll cooperating with a feed tray or a pair of feed rolls. Thereafter the fiber mass passes through an opening device formed, for example, of an opening roll which may be a needle roll or a fully spiked roll and thereafter the fiber material is advanced to a successive fiber processing machine.
In a known apparatus a fully spiked roll is provided which, as an opening roll, cooperates with a screen positioned therebelow. The screen surface has a plurality of passages such as holes or narrow slots whose length dimension is oriented parallel to the axis of the fully spiked roll. The screen is coaxial with the fully spiked roll and is at a distance from the beating circle of the pins so that the fiber material is guided over the screen. A planar horizontal cover is positioned above the fully spiked roll which is associated with a pneumatic device for removing the fiber material. The impurities pass through the apertures of the screen and are collected in a large waste chamber. It is a disadvantage of this prior art construction that the screen is expensive to manufacture and further, the screen apertures may become clogged during operation, particularly if the cotton undergoing processing is contaminated with sticky substances such as honeydew. Such occurrence adversely affects the cleaning efficiency. It is a further disadvantage of the prior art construction that upon increasing the circumferential speed of the fully spiked roll a damage to the fibers by the vigorous working of the pins on the slowly advanced fiber material may occur and therefore limits have to be set for the circumferential roll speed.